Physics · Science General

Collisions, Momentum and Kinetic Energy

331 Questions

Collisions, momentum, and kinetic energy questions analyze the principles of elastic and inelastic impacts. They require calculating mass, velocity, and conserved energy during physical interactions. These foundational physics topics are essential for most government engineering and general science examinations.

Elastic collisionsInelastic collisionsMomentum calculationKinetic energy principlesVelocity after impact

Collisions, Momentum and Kinetic Energy Questions

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

Which of the following statements are true?

  1. When the mass of a body is doubled then the momentum of a body is also doubled, provided the body maintains the same velocity.

  2. We feel pain in the hand on hitting the wall, this is a consequence of Newton's third law of motion.

  3. A table cloth can be pulled from a table without dislodging the dishes. This is due to inertia of rest.

  4. Momentum is a vector quantity.
Reveal answer Fill a bubble to check yourself
A,B,C,D Correct answer
Explanation

Option A is correct .

as P = mv,
So $ P \space \alpha \space m $ if v is constant.


Option B is correct.
The pain in hand is due to reaction from the wall. It will be same in magnitude as that of applied force according to Newton's third law, for every action, there is an equal and opposite reaction.


Option C is correct.
When table cloth is pulled very fast, due to inertia dishes does not change its state. 

Option 4 is correct.
P = mv
as v (velocity) is vector, momentum is also vector.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

two bodies having $K.E 4 J $ and $9 J$ have equal mass. And their momentum are $p _1$ and $p _2$ respectively then $p _1/p _2$

  1. $4:9$
  2. $9:4$
  3. $3:2$
  4. $2:3$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Kinetic energy is related to momentum by the formula K = p^2 / (2m). Since mass m is equal for both bodies, momentum p is proportional to the square root of kinetic energy K. Thus, p1/p2 = sqrt(K1/K2) = sqrt(4/9) = 2/3.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

The changes in a momentum of a particle,when the kinetic energy is increased by 0.1% will be:-

  1. 0.05%

  2. 0.1%

  3. 1.0%

  4. 10%
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

\begin{array}{l} The\, \, kineticenergyisE=\frac { 1 }{ 2 } m{ v^{ 2 } } \ The\, \, \, momentum\, \, is\, \, p=mv \ v=\sqrt { \frac { { 2E } }{ m }  }  \ therefore, \ \Rightarrow p=mv=m\sqrt { \frac { { 2E } }{ m }  } =\sqrt { 2mE }  \ taking\, \log  s, \ \Rightarrow \log  \, p=\frac { 1 }{ 2 } \left( { \log  2+\log  m+\log  \, E } \right)  \ differentiating: \ \Rightarrow \frac { { \Delta \, p } }{ p } =\frac { 1 }{ 2 } \left( { \frac { { \Delta m } }{ m }  } \right) +\frac { 1 }{ 2 } \left( { \frac { { \Delta E } }{ E }  } \right)  \ but, \ \Rightarrow \frac { { \Delta E } }{ E } =0.1 \ so.\, therefore, \ \Rightarrow \frac { { \Delta p } }{ p } =\frac { 1 }{ 2 } \times 0.1=0.05 \ so\, the\, correct\, option\, is\, A. \end{array}

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

A metal ball does not rebound when struck on a wall, whereas a rubber ball of same mass when thrown with the same velocity on the wall rebounds. From this it is inferred that:

  1. change in momentum is same in both.

  2. change in momentum in rubber ball is more.

  3. change in momentum in metal ball is more.

  4. initial momentum of metal ball is more than that of rubber ball.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Rubber ball has got more elasticity and the change in velocity is more in case of rubber ball which proves that change in momentum of rubber ball is more.

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

Two balls A and B of masses $m$ and $2m$ are in motion with velocities $2v$ and $v$ respectively. What is the ratio of their momentum ?

  1. 1:2

  2. 2:1

  3. 1:1

  4. 4:1
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

(i) Inertia depends on mass, and since the mass of the two balls are $m$ and $2m$, So the ratio of inertia of the balls $1 : 2$

(ii)Momentum , $ p = mv$
So, as per momentum equation, it depends on both mass and velocity.
So, their ratio $= m \times  2v : 2m \times  v = 1: 1$


Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

A body of mass m moving with a velocity v is acted upon by a force. Write expression for change in momentum  when $v\rightarrow c$.

  1. $m \Delta v$
  2. $\Delta \left( mv \right)$
  3. $v \Delta\left(m \right)$
  4. $mv$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As we know that momentum (p) =MAASS$\times$VELOCITY(vector quantity)
hence chance in momentum($\Delta$p)=${{m} _{2}{v} _{2}}-{{m} _{1}{v} _{1}}$=$\Delta$(mv)
where ${m} _{1}$=${m} _{2}$=m
$\Delta$v=${v} _{2}-{v} _{1}$

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

The linear momentum of a ball of mass $50  g$ is $0.5  kg  { m  s }^{ -1 }$. Find its velocity.

  1. $0.01$ ${ m s }^{ -1 }$
  2. $1$ ${ m s }^{ -1 }$
  3. $5$ ${ m s }^{ -1 }$
  4. $10$ ${ m s }^{ -1 }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

We know that $ p= mv$
where $p =0.5 kg ms^{-1}$ linear momentum
$m=50g = 0.05kg$ mass, $v =$ velocity
$\therefore v = \dfrac{p}{m}$
$\Rightarrow =\dfrac{0.5}{0.05} = 10 m/s$

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

A body of mass $5   kg$ is moving with velocity $2  { ms }^{ -1 }$. Calculate its linear momentum. 

  1. $2.5$ $kg$ ${ ms }^{ -1 }$
  2. $10$ $kg$ ${ ms }^{ -1 }$
  3. $5$ $kg$ ${ ms }^{ -1 }$
  4. $20$ $kg$ ${ ms }^{ -1 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We know that $ p= mv$


where $p =$ linear momentum

$m=5kg$ mass, $v =2 m/s$ velocity

$ p = 5 \times 2 = 10 kg ms^{-1}$

Multiple choice physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

A body P has mass 2 m and velocity 5 v. Another body Q has mass 8 m and velocity 1.25 v. Find out the ratio of momentum of P and Q.

  1. 2:1

  2. 1:1

  3. 1:2

  4. 3:2
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The momentum is given as $M= mv$

Where, $m= $ mass of object, 
              $v= $ velocity of object
Momentum of first object $= 2m\times 5v = 10mv$
Momentum of second object $= 8m\times 1.25v=10mv$, taking the ratio of the magnitude of momentum of Ist and IInd objects $ |p _1|:|p _2|= 1:1$
Hence, correct answer is B.